Re: Why is selectrow_hashref complaining about a fetch without execute?

On Mon, Jul 13, 2015 at 03:53:43PM -0700, David E. Wheeler wrote:
>    DBIers,
>    Got a complaint about a “fetch() without execute()” error. Asked for a trace, got this. Looks like
>    it’s coming from selectrow_hashref()? That shouldn’t happen, right?
> 
>      $ DBI_TRACE=1 sqitch status

Trace level 1 is handy when you just want a summary of what's going on.
If something odd is happening then you'd want at least trace level 2
so you see the method _calls_ as well as the _returns_.
For investigating mysterious happenings then higher trace levels,
like 4 thru 15, are more appropriate. 4 is usually sufficient.

I can't see anything obvious from this trace. Come back with a level 4
trace and hopefully that'll shed sufficient light.

Tim.

>      <- STORE('dbi_connect_closure', CODE(0x1c11b10))= ( 1 ) [1 items] at DBI.pm line 742
>      <- FETCH('mysql_serverinfo')= ( '5.6.17-0ubuntu0.14.04.1-log' ) [1 items] at mysql.pm line 106
>      <- FETCH('mysql_serverversion')= ( '50617' ) [1 items] at mysql.pm line 109
>      !! The ERROR '1038' was CLEARED by call to fetchrow_hashref method
>      !! The ERROR '4' was CLEARED by call to fetch method
>         ERROR: 19 'fetch() without execute()' (err#0)
>      <- DESTROY(DBI::st=HASH(0x2ae9638))= ( undef ) [1 items] at DBI.pm line 1639
>      !! ERROR: 19 'fetch() without execute()' (err#0)
>      <- selectrow_hashref('
>          SELECT c.change_id ...
>               , c.planned_a...', undef, ...)= ( undef ) [1 items] at DBIEngine.pm line 116
>      -> HandleError on DBI::db=HASH(0x2b9ea48) via CODE(0x278aa80) (undef)
>      <- $DBI::state= 'S1000'
>      <- $DBI::state= 'S1000'
>      <- $DBI::state= 'S1000'
>      <- $DBI::state= 'S1000'
>      <- $DBI::state= 'S1000'
>      !! The ERROR '19' was CLEARED by call to selectcol_arrayref method
>      <- DESTROY(DBI::st=HASH(0x2ae94b8))= ( undef ) [1 items] at mysql.pm line 218
>      <- selectcol_arrayref('
>          SELECT COUNT(*)
>            FROM information_schema.tables
>           WHERE table_schema = ?
>             AND table_name   = ?
>      ', undef, ...)= ( [ '1' ] ) [1 items] at mysql.pm line 218
>      <- DESTROY(DBI::db=HASH(0x2b9ea48))= ( undef ) [1 items] at Tiny.pm line 88
>  fetch() without execute()
>      <- disconnect_all= ( ) [0 items] (not implemented) at DBI.pm line 750
>  !   <- DESTROY(DBI::dr=HASH(0x1c119a8))= ( undef ) [1 items] during global destruction
> 
>    Thanks,
>    David
>    Reverse link: [1]unknown
> 
> References
> 
>    Visible links
>    1. https://github.com/theory/sqitch/issues/235#issuecomment-120180277